In this paper,the performance of the classic snowmelt runoff model(SRM)is evaluated in a daily discharge simulation with two different melt models,the empirical temperature-index melt model and the energy-based radiat...In this paper,the performance of the classic snowmelt runoff model(SRM)is evaluated in a daily discharge simulation with two different melt models,the empirical temperature-index melt model and the energy-based radiation melt model,through a case study from the data-sparse mountainous watershed of the Urumqi River basin in Xinjiang Uyghur Autonomous Region of China.The classic SRM,which uses the empirical temperature-index method,and a radiation-based SRM,incorporating shortwave solar radiation and snow albedo,were developed to simulate daily runoff for the spring and summer snowmelt seasons from 2005 to 2012,respectively.Daily meteorological and hydrological data were collected from three stations located in the watershed.Snow cover area(SCA)was extracted from satellite images.Solar radiation inputs were estimated based on a digital elevation model(DEM).The results showed that the overall accuracy of the classic SRM and radiation-based SRM for simulating snowmeltdischarge was relatively high.The classic SRM outperformed the radiation-based SRM due to the robust performance of the temperature-index model in the watershed snowmelt computation.No significant improvement was achieved by employing solar radiation and snow albedo in the snowmelt runoff simulation due to the inclusion of solar radiation as a temperature-dependent energy source and the local pattern of snowmelt behavior throughout the melting season.Our results suggest that the classic SRM simulates daily runoff with favorable accuracy and that the performance of the radiation-based SRM needs to be further improved by more ground-measured data for snowmelt energy input.展开更多
Against the background of climate change, alpine permafrost active layers have shown a gradual thickening trend and the hydrothermal conditions have undergone significant changes in the Tianshan Mountains and the Qing...Against the background of climate change, alpine permafrost active layers have shown a gradual thickening trend and the hydrothermal conditions have undergone significant changes in the Tianshan Mountains and the Qinghai-Tibet Plateau, China. At the ice-free cirque basins in the headwaters of the Urumqi River （hereafter referred to as the Ice-Free Cirque） in eastern Tianshan, China, the hydrological effects of the alpine permafrost active layers appear to have also exhibited sig- nificant changes recently. The increasing trend of local precipitation is clear in May and June. The onset of winter and spring snowmelt runoff clearly lags behind increases of air temperature, and the runoff peak appears near the beginning of the melting season, which results in the spring rtmoff increasing. In summer, runoff decreases strongly and the maximum runoff occurs earlier. In our analysis of meteorological and hydrologic data from 1959 to 2010, the runoffand precipitation changes are significantly correlated. In the initial stage of runoff, the runoff-producing process is mainly under the control of the soil water content and soil temperature in the 0-30 cm active layers. Spring precipitation and snowmelt water are mainly involved in the processes of infiltration and evaporation while some melt water infiltrates into the seasonal thawed layer and stays above the frozen layers. During the strong ablation period in summer, the runoff-generating process is mainly controlled by soil water content in the active layers deeper than 60 cm. In the active layer, precipitation and sea- sonal snowmelt water infiltrates, migrates, collects, and then forms runoff.展开更多
We report on the properties of strong pulses from PSR B0656＋14 by analyzing the data obtained using the Urumqi 25-m radio telescope at 1540 MHz from August 2007 to September 2010.In 44 h of observational data,a total...We report on the properties of strong pulses from PSR B0656＋14 by analyzing the data obtained using the Urumqi 25-m radio telescope at 1540 MHz from August 2007 to September 2010.In 44 h of observational data,a total of 67 pulses with signal-to-noise ratios above a 5σthreshold were detected.The peak flux densities of these pulses are 58 to 194 times that of the average profile,and their pulse energies are 3 to 68 times that of the average pulse.These pulses are clustered around phases about 5-ahead of the peak of the average profile.Compared with the width of the average profile,they are relatively narrow,with the full widths at half-maximum ranging from 0.28 ° to 1.78 °.The distribution of pulse-energies follows a lognormal distribution.These sporadic strong pulses detected from PSR B0656＋14 have different characteristics from both typical giant pulses and its regular pulses.展开更多
An automated procedure employing principal-component analysis and a two-stage cluster analysis was developed to classify the synoptic meteorological conditions prevailing over Urumqi, one of the most heavily polluted ...An automated procedure employing principal-component analysis and a two-stage cluster analysis was developed to classify the synoptic meteorological conditions prevailing over Urumqi, one of the most heavily polluted cities in the world. Six clusters representing different circulation patterns and air-mass characteristics were classified using surface- and upper-meteorological variables during the heating period from 2001 to 2008, and the relationships between synoptic clusters and air quality were evaluated. The heaviest air-pollution episodes occurred when Urumqi was in either an extremely cold, strong anticyclone or at the front of a migrating cyclone, both with light winds, wet surface air, and relatively dry upper air. Moderate pollution was seen when Urumqi was in the pre-cold/cold frontal passages with lower temperatures and light winds or moderate anticyclone with relatively warmer, drier air. When Urumqi was at the front of a migrating anticyclone or in a weak anticyclone with moderate winds and most warm, dry air, or in the cold/post-cold frontal passages with relatively strongly northerly airflows and precipitation, relatively good air quality could be seen. These results suggest that air pollution in Urumqi is very closely related to the synoptic meteorological conditions, which provides an important basis for not only the prediction and control of urban air-quality problems here but also for the analysis of the differential impacts of weather and pollution on human morbidity.展开更多
The purpose of this study is to investigate the Classification of Synoptic Circulation Patterns for Fog in the Urumqi Airport in Xinjiang, China. By using relevant climate statistical method, the hourly ground observa...The purpose of this study is to investigate the Classification of Synoptic Circulation Patterns for Fog in the Urumqi Airport in Xinjiang, China. By using relevant climate statistical method, the hourly ground observation data and four times per day and NCEP/NCAR reanalysis data (1° × 1°) from 1985 to 2014 were analyzed. The results showed that: 1) The occurrence of fog significantly increased during 1985 and 2014;There are two stages of the airport fog in the 30 years, less-fog period (1985-2002) and more-fog period (2002-2014), the fog focused occurred in November to March of the following year, most in December and least in March;2) Based on Lamb-Jenkinson method, the dominant types of fog in Urumqi Airport are C, E, SE, W, A types (Among them, A, C, E, W, SE are the circulation types. C is Cyclone, A is Anti-cyclone, E is East, W is West, SE is Southeast), and the international distribution of each type is also different;3) The dominant types of persistence fog are A, C, E, SE types, A type appears in the afternoon to the nighttime, in the morning less frequent, on the other hand, C type is just the opposite;4) Atmospheric circulation characteristics for persistence fog profile can be divided into four series: A, C, E, SE series, and climatic characteristics in different series are different.展开更多
We have made careful field investigation and trench exploration to the Xishan fault system in west of Urumqi, and an integrated analysis in conjunction with data of deep seismic sounding. Our result suggests that unde...We have made careful field investigation and trench exploration to the Xishan fault system in west of Urumqi, and an integrated analysis in conjunction with data of deep seismic sounding. Our result suggests that under the SN-oriented compressive stress, the Xishan block moves steadily toward the Tianshan Mountains in south, resulting in southward thrust-slip and crustal shortening, particularly the southward thrust of the Xishan fault which serves as the main boundary in south. North of the Xishan fault are the Wangjiagou fault and Jiujiawan fault which are the secondary faults associated with the Xishan fault in generation. Both faults have slippage along horizons during the uplift of the Xishan block, and the Jiujiawan fault has also a component of normal faulting due to the influence of the Bogeda nappe structure. These two faults accommodate the fold deformation of the hanging wall of the Xishan fault, thus the Xishan fault-bounded swell is characterized by monocline. All secondary faults of the Xishan fault system constitute a common seismogenic structural system, so that their seismic hazards should be considered in an equal manner.展开更多
Objective To investigate the prevalence of obesity and distribution of body mass index （BMI） in school children of four ethnic groups in Urumqi, Xinjiang, China. Methods A total of 55 508 school children of Han, Hui...Objective To investigate the prevalence of obesity and distribution of body mass index （BMI） in school children of four ethnic groups in Urumqi, Xinjiang, China. Methods A total of 55 508 school children of Han, Hui, Uygur and Kazak nationalities aged 8-18 years were selected by a cluster sampling from a districts of Urumqi City for anthropometrie measurement and demographic survey. Prevalence of obesity and overweight and distribution of body mass index （BMI） by gender, age, and nationality were analyzed and compared. Cutoff points of BMI for defining obesity and overweight were based on the proposal set by the Working Group on Obesity in China （WGOC） to assess age-, gender- and nationality-specific prevalence of obesity and overweight. Results Prevalence of obesity was 5.34%, 6.78%, 3.39 %, and 1.22% for boys and 2.61%, 1.83%, 1.78%, and 1.40% for girls of Han, Hui, Uygur and Kazak nationalities, respectively. Prevalence of obesity tended to decrease with age overall, whereas that of overweight increased with age in Han children. Conclusions Prevalence of obesity in school children in Urumqi varies with their nationalities and is lower than that of an average national level and a level of western countries. Obesity is more prevalent in boys than in girls of Urmuqi overall, which is just the opposite in Kazak children. Han boys and Hui girls have the highest prevalence of obesity and Kazak boys and girls have the lowest ones. Prevalence of obesity decreases with age, but that of overweight shows a different trend.展开更多
In this paper, Urumqi Airport time-lapse ground man-made observation data from November 2015 to February 2017, European fine grid (0.25 × 0.25) initial field (20 o’clock) and the forecast field within 24 hours w...In this paper, Urumqi Airport time-lapse ground man-made observation data from November 2015 to February 2017, European fine grid (0.25 × 0.25) initial field (20 o’clock) and the forecast field within 24 hours were utilized. From November 2015 to February 2016, the relevant materials were used as research samples (a total of 948 times), and from November 2016 to February 2017 as test samples (a total of 922 times), statistical methods were used to establish the scoring standards. And each relevant element was scored. After the score, the score level range was delineated, and the visibility forecast was performed according to the scope. The conclusions are as follows: 1) European fine grid forecast products are with good correspondence with the visibility of this field are 850 hPa and 2 m high temperature inversion, 850 hPa relative humidity and 850 hPa wind field over the field. 2) Through the statistical analysis of scores, it is defined that the score below 400 is level 4, the score above 1000 is level 1, the difference is significant, and the forecast indication is strong. Level 2 and level 3 are more evenly distributed, with no more concentrated fractions. 3) Applying the test sample to test the above indicators. The forecast accuracy of level 1 is 61.2%, and the forecast accuracy of level 4 is 97.2%, so level 1 and level 4 are expected to obtain better forecast results, which is of practical application value.展开更多
The Sun affects physical phenomena on Earth in multiple ways. In particular, the material in interplanetary space comes from coronal expansion in the form of inhomogeneous plasma flow （solar wind）, which is the prim...The Sun affects physical phenomena on Earth in multiple ways. In particular, the material in interplanetary space comes from coronal expansion in the form of inhomogeneous plasma flow （solar wind）, which is the primary source of the interplanetary medium. Ground-based Interplanetary Scintillation （IPS） observations are an important and effective method for measuring solar wind speed and the structures of small diameter radio sources. We discuss one mode of ground-based single-station observations： Single-Station Single-Frequency （SSSF） mode. To study the SSSF mode, a new system has been established at Urumqi Astronomical Observatory （UAO）, China, and a series of experimental observations were successfully carried out from May to December, 2008.展开更多
The air pollution in Urumqi which is located on the northern slope of the Tianshan Mountains in northwestern China,is very serious in winter.Of particular importance is the influence of terrain-induced shallow foehn,k...The air pollution in Urumqi which is located on the northern slope of the Tianshan Mountains in northwestern China,is very serious in winter.Of particular importance is the influence of terrain-induced shallow foehn,known locally as elevated southeasterly gale(ESEG).It usually modulates atmospheric boundary layer structure and wind field patterns and produces favorable meteorological conditions conducive to hazardous air pollution.During 2013-17,Urumqi had an average of 50 d yr-1 of heavy pollution(daily average PM2.5 concentration>150μg m-3),of which 41 days were in winter.The majority(71.4%)of heavy pollution processes were associated with the shallow foehn.Based on microwave radiometer,wind profiler,and surface observations,the surface meteorological fields and boundary layer evolution during the worst pollution episode in Urumqi during 16-23 February 2013 are investigated.The results illustrate the significant role of shallow foehn in the building,strengthening,and collapsing of temperature inversions.There were four wind field patterns corresponding to four different phases during the whole pollution event.The most serious pollution phase featured shallow foehn activity in the south of Urumqi city and the appearance of an intense inversion layer below 600 m.Intense convergence caused by foehn and mountain-valley winds was sustained during most of the phase,resulting in pollutants sinking downward to the lower boundary layer and accumulating around urban area.The key indicators of such events identified in this study are highly correlated to particulate matter concentrations and could be used to predict heavy pollution episodes in the feature.展开更多
Objective:To determine whether a variant(Pl^A2)of the membrane glycoprotein Ⅲa(GP Ⅲa)gene is associated with CAD,Furthermore,the association of the polymorphism with the classical risk factors was analyzed.Methods:B...Objective:To determine whether a variant(Pl^A2)of the membrane glycoprotein Ⅲa(GP Ⅲa)gene is associated with CAD,Furthermore,the association of the polymorphism with the classical risk factors was analyzed.Methods:Blood was drawn from 105 patients(pt) and 56 controls,some of those undergoing angiography,A 266 base pair fragment of the GP Ⅲa gene was amplified by the polymerase chain reaction(PCR) and digestewd with the MspI restriction enzyme.Genotypes were identified after electrophoresis of digestion products in 2.0% a-garose gel.Results:Of the 105 patients(pt). 65 had acute (n=19) or previous MI,20 had unstable angina (UAP),and 20 had stable angina(SAP) .The Pl^A2 allele was carried by 0% of CAD pt versus 7.7% of Non-CAD control subjects in Uygur population.The Pl^A2 allele was found in 0% of CAD pt versus 0% of Non-CAD control subjects in Han population.Conclusions:the Pl^A2 variant of the gene GP Ⅲa is not associated with CAD in Uygur population and Han population in Urunqi city of Xinjiang Uygur Autonomous Region.展开更多
In this paper, an approach to simulate the spatial dis- tribution of urban population is proposed using urban land use and population statistical data through the geographical information systems (GIS). Then, the spat...In this paper, an approach to simulate the spatial dis- tribution of urban population is proposed using urban land use and population statistical data through the geographical information systems (GIS). Then, the spatial population distribution of Urumqi as a case is simulated by the approach mentioned above and its varying patterns are analyzed by the raster population surface. As a result, producing raster population surface is more accurate and natural than the traditional choropleth map of population density. Concerning the spatial population distribution of Urumqi, the population density declines from south to north and the population distribution mainly presents "T-type", the population distribution presents multi-centre agglomeration and the population distribu- tion of the districts shows different features. The population den- sity varies significantly with the increase in the distance from central business district (CBD). Finally, it is found in this paper that the development history of districts, terrain and traffic road are main factors that have an influence Urumqi’s population dis- tribution. This paper tries to provide more accurate population data for the plan and management of urban land, traffic and public facilities in order to enrich the researches on urban population distribution.展开更多
A maser spectral line system is newly implemented on the Urumqi 25m Radio Telescope. The system consists mainly of a cooling receiver and a 4096 channels digital correlation spectrometer. The frequency resolution of t...A maser spectral line system is newly implemented on the Urumqi 25m Radio Telescope. The system consists mainly of a cooling receiver and a 4096 channels digital correlation spectrometer. The frequency resolution of the spectrometer at the maximum signal bandwidth of 80MHz is 19.5kHz. After careful calibrations observation at the 1665 MHz OH maser emission was made towards a number of sources, including W49N and W75N. The observed results demonstrate that the digital correlation spectrometer is suitable for astronomical spectral line observations.展开更多
Excessive accumulation of zinc(Zn)in urban soil can lead to environmental pollution and pose a potential threat to human health and the ecosystem.How to quickly and accurately monitor the urban soil zinc content on a ...Excessive accumulation of zinc(Zn)in urban soil can lead to environmental pollution and pose a potential threat to human health and the ecosystem.How to quickly and accurately monitor the urban soil zinc content on a large scale in real time and dynamically is crucial.Hyperspectral remote sensing technology provides a new method for rapid and nondestructive soil property detection.The main goal of this study is to find an optimal combination of spectral transformation and a hyperspectral estimation model to predict the Zn content in urban soil.A total of 88 soil samples were collected to obtain the Zn contents and related hyperspectral data,and perform 18 transformations on the original spectral data.Then,select important wavelengths by Pearson’s correlation coefficient analysis(PCC)and CARS.Finally,establish a partial least squares regression model(PLSR)and random forest regression model(RFR)with soil Zn content and important wavelengths.The results indicated that the average Zn content of the collected soil samples is 60.88 mg/kg.Pearson’s correlation coefficient analysis(PCC)and CARS for the original and transformed wavelengths can effectively improve the correlations between the spectral data and soil Zn content.The number of important wavelengths selected by CARS is less than the important wavelengths selected by PCC.Partial least squares regression model based on first-order differentiation of the reciprocal by CARS(CARS-RTFD-PLSR)is more stable 2 and has the highest prediction ability(R=0.937,RMSE=8.914,MAE=2.735,RPD=3.985).The CARS-RTFD-PLSR method can be used as a means of prediction of Zn content in soil in oasis cities.The results of the study can provide technical support for the hyperspectral estimation of the soil Zn content.展开更多
基金funded by the National Natural Science Foundation of China (41771470, 51069017 and 41261090)
文摘In this paper,the performance of the classic snowmelt runoff model(SRM)is evaluated in a daily discharge simulation with two different melt models,the empirical temperature-index melt model and the energy-based radiation melt model,through a case study from the data-sparse mountainous watershed of the Urumqi River basin in Xinjiang Uyghur Autonomous Region of China.The classic SRM,which uses the empirical temperature-index method,and a radiation-based SRM,incorporating shortwave solar radiation and snow albedo,were developed to simulate daily runoff for the spring and summer snowmelt seasons from 2005 to 2012,respectively.Daily meteorological and hydrological data were collected from three stations located in the watershed.Snow cover area(SCA)was extracted from satellite images.Solar radiation inputs were estimated based on a digital elevation model(DEM).The results showed that the overall accuracy of the classic SRM and radiation-based SRM for simulating snowmeltdischarge was relatively high.The classic SRM outperformed the radiation-based SRM due to the robust performance of the temperature-index model in the watershed snowmelt computation.No significant improvement was achieved by employing solar radiation and snow albedo in the snowmelt runoff simulation due to the inclusion of solar radiation as a temperature-dependent energy source and the local pattern of snowmelt behavior throughout the melting season.Our results suggest that the classic SRM simulates daily runoff with favorable accuracy and that the performance of the radiation-based SRM needs to be further improved by more ground-measured data for snowmelt energy input.
基金supported by the Natural Science Foundation of China(Nos.41271035 and 41201060)Chinese Academy of Sciences and the National Scientific and Technological Support Projects(KJZD-EW-G03-04,2013BAB05B03)
文摘Against the background of climate change, alpine permafrost active layers have shown a gradual thickening trend and the hydrothermal conditions have undergone significant changes in the Tianshan Mountains and the Qinghai-Tibet Plateau, China. At the ice-free cirque basins in the headwaters of the Urumqi River （hereafter referred to as the Ice-Free Cirque） in eastern Tianshan, China, the hydrological effects of the alpine permafrost active layers appear to have also exhibited sig- nificant changes recently. The increasing trend of local precipitation is clear in May and June. The onset of winter and spring snowmelt runoff clearly lags behind increases of air temperature, and the runoff peak appears near the beginning of the melting season, which results in the spring rtmoff increasing. In summer, runoff decreases strongly and the maximum runoff occurs earlier. In our analysis of meteorological and hydrologic data from 1959 to 2010, the runoffand precipitation changes are significantly correlated. In the initial stage of runoff, the runoff-producing process is mainly under the control of the soil water content and soil temperature in the 0-30 cm active layers. Spring precipitation and snowmelt water are mainly involved in the processes of infiltration and evaporation while some melt water infiltrates into the seasonal thawed layer and stays above the frozen layers. During the strong ablation period in summer, the runoff-generating process is mainly controlled by soil water content in the active layers deeper than 60 cm. In the active layer, precipitation and sea- sonal snowmelt water infiltrates, migrates, collects, and then forms runoff.
基金funded by the National Natural Science Foundation of China(Grant No.10973026)
文摘We report on the properties of strong pulses from PSR B0656＋14 by analyzing the data obtained using the Urumqi 25-m radio telescope at 1540 MHz from August 2007 to September 2010.In 44 h of observational data,a total of 67 pulses with signal-to-noise ratios above a 5σthreshold were detected.The peak flux densities of these pulses are 58 to 194 times that of the average profile,and their pulse energies are 3 to 68 times that of the average pulse.These pulses are clustered around phases about 5-ahead of the peak of the average profile.Compared with the width of the average profile,they are relatively narrow,with the full widths at half-maximum ranging from 0.28 ° to 1.78 °.The distribution of pulse-energies follows a lognormal distribution.These sporadic strong pulses detected from PSR B0656＋14 have different characteristics from both typical giant pulses and its regular pulses.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No. KZCX1-YW-06-01)
文摘An automated procedure employing principal-component analysis and a two-stage cluster analysis was developed to classify the synoptic meteorological conditions prevailing over Urumqi, one of the most heavily polluted cities in the world. Six clusters representing different circulation patterns and air-mass characteristics were classified using surface- and upper-meteorological variables during the heating period from 2001 to 2008, and the relationships between synoptic clusters and air quality were evaluated. The heaviest air-pollution episodes occurred when Urumqi was in either an extremely cold, strong anticyclone or at the front of a migrating cyclone, both with light winds, wet surface air, and relatively dry upper air. Moderate pollution was seen when Urumqi was in the pre-cold/cold frontal passages with lower temperatures and light winds or moderate anticyclone with relatively warmer, drier air. When Urumqi was at the front of a migrating anticyclone or in a weak anticyclone with moderate winds and most warm, dry air, or in the cold/post-cold frontal passages with relatively strongly northerly airflows and precipitation, relatively good air quality could be seen. These results suggest that air pollution in Urumqi is very closely related to the synoptic meteorological conditions, which provides an important basis for not only the prediction and control of urban air-quality problems here but also for the analysis of the differential impacts of weather and pollution on human morbidity.
文摘The purpose of this study is to investigate the Classification of Synoptic Circulation Patterns for Fog in the Urumqi Airport in Xinjiang, China. By using relevant climate statistical method, the hourly ground observation data and four times per day and NCEP/NCAR reanalysis data (1° × 1°) from 1985 to 2014 were analyzed. The results showed that: 1) The occurrence of fog significantly increased during 1985 and 2014;There are two stages of the airport fog in the 30 years, less-fog period (1985-2002) and more-fog period (2002-2014), the fog focused occurred in November to March of the following year, most in December and least in March;2) Based on Lamb-Jenkinson method, the dominant types of fog in Urumqi Airport are C, E, SE, W, A types (Among them, A, C, E, W, SE are the circulation types. C is Cyclone, A is Anti-cyclone, E is East, W is West, SE is Southeast), and the international distribution of each type is also different;3) The dominant types of persistence fog are A, C, E, SE types, A type appears in the afternoon to the nighttime, in the morning less frequent, on the other hand, C type is just the opposite;4) Atmospheric circulation characteristics for persistence fog profile can be divided into four series: A, C, E, SE series, and climatic characteristics in different series are different.
基金supported by Active Fault Detection and Earthquake Risk Estimation of Urumqi (1-4-31)Sub-topic of National Science and Technology Support Project (2006BAC13B010102)International Cooperation Key Project of Ministry of Science and Technology "Research on New Methods of Earthquake Prediction and Risk Estimation"(2004BFBA0005)
文摘We have made careful field investigation and trench exploration to the Xishan fault system in west of Urumqi, and an integrated analysis in conjunction with data of deep seismic sounding. Our result suggests that under the SN-oriented compressive stress, the Xishan block moves steadily toward the Tianshan Mountains in south, resulting in southward thrust-slip and crustal shortening, particularly the southward thrust of the Xishan fault which serves as the main boundary in south. North of the Xishan fault are the Wangjiagou fault and Jiujiawan fault which are the secondary faults associated with the Xishan fault in generation. Both faults have slippage along horizons during the uplift of the Xishan block, and the Jiujiawan fault has also a component of normal faulting due to the influence of the Bogeda nappe structure. These two faults accommodate the fold deformation of the hanging wall of the Xishan fault, thus the Xishan fault-bounded swell is characterized by monocline. All secondary faults of the Xishan fault system constitute a common seismogenic structural system, so that their seismic hazards should be considered in an equal manner.
文摘Objective To investigate the prevalence of obesity and distribution of body mass index （BMI） in school children of four ethnic groups in Urumqi, Xinjiang, China. Methods A total of 55 508 school children of Han, Hui, Uygur and Kazak nationalities aged 8-18 years were selected by a cluster sampling from a districts of Urumqi City for anthropometrie measurement and demographic survey. Prevalence of obesity and overweight and distribution of body mass index （BMI） by gender, age, and nationality were analyzed and compared. Cutoff points of BMI for defining obesity and overweight were based on the proposal set by the Working Group on Obesity in China （WGOC） to assess age-, gender- and nationality-specific prevalence of obesity and overweight. Results Prevalence of obesity was 5.34%, 6.78%, 3.39 %, and 1.22% for boys and 2.61%, 1.83%, 1.78%, and 1.40% for girls of Han, Hui, Uygur and Kazak nationalities, respectively. Prevalence of obesity tended to decrease with age overall, whereas that of overweight increased with age in Han children. Conclusions Prevalence of obesity in school children in Urumqi varies with their nationalities and is lower than that of an average national level and a level of western countries. Obesity is more prevalent in boys than in girls of Urmuqi overall, which is just the opposite in Kazak children. Han boys and Hui girls have the highest prevalence of obesity and Kazak boys and girls have the lowest ones. Prevalence of obesity decreases with age, but that of overweight shows a different trend.
文摘In this paper, Urumqi Airport time-lapse ground man-made observation data from November 2015 to February 2017, European fine grid (0.25 × 0.25) initial field (20 o’clock) and the forecast field within 24 hours were utilized. From November 2015 to February 2016, the relevant materials were used as research samples (a total of 948 times), and from November 2016 to February 2017 as test samples (a total of 922 times), statistical methods were used to establish the scoring standards. And each relevant element was scored. After the score, the score level range was delineated, and the visibility forecast was performed according to the scope. The conclusions are as follows: 1) European fine grid forecast products are with good correspondence with the visibility of this field are 850 hPa and 2 m high temperature inversion, 850 hPa relative humidity and 850 hPa wind field over the field. 2) Through the statistical analysis of scores, it is defined that the score below 400 is level 4, the score above 1000 is level 1, the difference is significant, and the forecast indication is strong. Level 2 and level 3 are more evenly distributed, with no more concentrated fractions. 3) Applying the test sample to test the above indicators. The forecast accuracy of level 1 is 61.2%, and the forecast accuracy of level 4 is 97.2%, so level 1 and level 4 are expected to obtain better forecast results, which is of practical application value.
基金supported by the National Meridian Project (Grant No [2006]2176)
文摘The Sun affects physical phenomena on Earth in multiple ways. In particular, the material in interplanetary space comes from coronal expansion in the form of inhomogeneous plasma flow （solar wind）, which is the primary source of the interplanetary medium. Ground-based Interplanetary Scintillation （IPS） observations are an important and effective method for measuring solar wind speed and the structures of small diameter radio sources. We discuss one mode of ground-based single-station observations： Single-Station Single-Frequency （SSSF） mode. To study the SSSF mode, a new system has been established at Urumqi Astronomical Observatory （UAO）, China, and a series of experimental observations were successfully carried out from May to December, 2008.
基金supported by Central Scientific Research and Operational Project (IDM2020001)National Natural Science Foundation of China (Grant No. 41575011)China Desert Funds (Sqj2017013, Sqj2019004)
文摘The air pollution in Urumqi which is located on the northern slope of the Tianshan Mountains in northwestern China,is very serious in winter.Of particular importance is the influence of terrain-induced shallow foehn,known locally as elevated southeasterly gale(ESEG).It usually modulates atmospheric boundary layer structure and wind field patterns and produces favorable meteorological conditions conducive to hazardous air pollution.During 2013-17,Urumqi had an average of 50 d yr-1 of heavy pollution(daily average PM2.5 concentration>150μg m-3),of which 41 days were in winter.The majority(71.4%)of heavy pollution processes were associated with the shallow foehn.Based on microwave radiometer,wind profiler,and surface observations,the surface meteorological fields and boundary layer evolution during the worst pollution episode in Urumqi during 16-23 February 2013 are investigated.The results illustrate the significant role of shallow foehn in the building,strengthening,and collapsing of temperature inversions.There were four wind field patterns corresponding to four different phases during the whole pollution event.The most serious pollution phase featured shallow foehn activity in the south of Urumqi city and the appearance of an intense inversion layer below 600 m.Intense convergence caused by foehn and mountain-valley winds was sustained during most of the phase,resulting in pollutants sinking downward to the lower boundary layer and accumulating around urban area.The key indicators of such events identified in this study are highly correlated to particulate matter concentrations and could be used to predict heavy pollution episodes in the feature.
文摘Objective:To determine whether a variant(Pl^A2)of the membrane glycoprotein Ⅲa(GP Ⅲa)gene is associated with CAD,Furthermore,the association of the polymorphism with the classical risk factors was analyzed.Methods:Blood was drawn from 105 patients(pt) and 56 controls,some of those undergoing angiography,A 266 base pair fragment of the GP Ⅲa gene was amplified by the polymerase chain reaction(PCR) and digestewd with the MspI restriction enzyme.Genotypes were identified after electrophoresis of digestion products in 2.0% a-garose gel.Results:Of the 105 patients(pt). 65 had acute (n=19) or previous MI,20 had unstable angina (UAP),and 20 had stable angina(SAP) .The Pl^A2 allele was carried by 0% of CAD pt versus 7.7% of Non-CAD control subjects in Uygur population.The Pl^A2 allele was found in 0% of CAD pt versus 0% of Non-CAD control subjects in Han population.Conclusions:the Pl^A2 variant of the gene GP Ⅲa is not associated with CAD in Uygur population and Han population in Urunqi city of Xinjiang Uygur Autonomous Region.
基金This study is supported by the Knowledge Innovation Project of CAS (Grant No. KZCS-SW-355).
文摘In this paper, an approach to simulate the spatial dis- tribution of urban population is proposed using urban land use and population statistical data through the geographical information systems (GIS). Then, the spatial population distribution of Urumqi as a case is simulated by the approach mentioned above and its varying patterns are analyzed by the raster population surface. As a result, producing raster population surface is more accurate and natural than the traditional choropleth map of population density. Concerning the spatial population distribution of Urumqi, the population density declines from south to north and the population distribution mainly presents "T-type", the population distribution presents multi-centre agglomeration and the population distribu- tion of the districts shows different features. The population den- sity varies significantly with the increase in the distance from central business district (CBD). Finally, it is found in this paper that the development history of districts, terrain and traffic road are main factors that have an influence Urumqi’s population dis- tribution. This paper tries to provide more accurate population data for the plan and management of urban land, traffic and public facilities in order to enrich the researches on urban population distribution.
基金Supported by the National Natural Science Foundation of China.
文摘A maser spectral line system is newly implemented on the Urumqi 25m Radio Telescope. The system consists mainly of a cooling receiver and a 4096 channels digital correlation spectrometer. The frequency resolution of the spectrometer at the maximum signal bandwidth of 80MHz is 19.5kHz. After careful calibrations observation at the 1665 MHz OH maser emission was made towards a number of sources, including W49N and W75N. The observed results demonstrate that the digital correlation spectrometer is suitable for astronomical spectral line observations.
基金funded by the National Natural Science Foundation of China(No.U2003301)the Tianshan Talent Training Project of Xinjiang.
文摘Excessive accumulation of zinc(Zn)in urban soil can lead to environmental pollution and pose a potential threat to human health and the ecosystem.How to quickly and accurately monitor the urban soil zinc content on a large scale in real time and dynamically is crucial.Hyperspectral remote sensing technology provides a new method for rapid and nondestructive soil property detection.The main goal of this study is to find an optimal combination of spectral transformation and a hyperspectral estimation model to predict the Zn content in urban soil.A total of 88 soil samples were collected to obtain the Zn contents and related hyperspectral data,and perform 18 transformations on the original spectral data.Then,select important wavelengths by Pearson’s correlation coefficient analysis(PCC)and CARS.Finally,establish a partial least squares regression model(PLSR)and random forest regression model(RFR)with soil Zn content and important wavelengths.The results indicated that the average Zn content of the collected soil samples is 60.88 mg/kg.Pearson’s correlation coefficient analysis(PCC)and CARS for the original and transformed wavelengths can effectively improve the correlations between the spectral data and soil Zn content.The number of important wavelengths selected by CARS is less than the important wavelengths selected by PCC.Partial least squares regression model based on first-order differentiation of the reciprocal by CARS(CARS-RTFD-PLSR)is more stable 2 and has the highest prediction ability(R=0.937,RMSE=8.914,MAE=2.735,RPD=3.985).The CARS-RTFD-PLSR method can be used as a means of prediction of Zn content in soil in oasis cities.The results of the study can provide technical support for the hyperspectral estimation of the soil Zn content.
